Various surgical procedures are routinely carried out intravascularly or intraluminally. For example, in the treatment of vascular disease, such as arteriosclerosis, it is a common practice to invade the artery and insert an instrument (e.g., a balloon or other type of catheter) to carry out a procedure within the artery. Such procedures usually involve the percutaneous puncture of the artery so that an insertion sheath can be placed in the artery and thereafter instruments (e.g., a catheter) can pass through the sheath and to an operative position within the artery. Intravascular and intraluminal procedures unavoidably present the problem of stopping the bleeding at the percutaneous puncture after the procedure has been completed and after the instruments (and any insertion sheaths used therewith) have been removed. Bleeding from puncture sites, particularly in the case of femoral arterial punctures, is typically stopped by utilizing vascular closure devices, such as those described in U.S. Pat. Nos. 6,045,569; 6,090,130; 7,618,436; 7,749,248; 7,837,705; 7,931,670; and, and related patents and patent applications, all of which are hereby incorporated by reference.
As noted above, vascular closure devices and processes associated therewith are commonly used to seal arteriotomies such as the ones created when the femoral artery is deliberately punctured in order to perform a procedure. The femoral artery is often punctured in order to clear blockages or obstructions in the patient's circulatory system. The above-mentioned patents describe embodiments of a puncture closure device in which an anchor is inserted through the arteriotomy and positioned against an interior wall of the artery. A sealant plug, such as a collagen sponge, is positioned at an exterior wall of the artery above the arteriotomy. The anchor and collagen sponge are then sandwiched or compressed together to facilitate rapid hemostasis and sealing of the arteriotomy. The anchor, positioned at an internal portion of the incision or opening, seals an internal side of the incision. Preferably, the anchor does not bend or weaken during the implantation process or until after a preferred time after implantation. After a certain period of time, the wound or incision heals, also during which time the anchor is reabsorbed.
The anchor is made of a biologically resorbable material, as the anchor is designed to resorb in the body. Generally, the material composing the anchor is chosen for the resorbtion time of the material in the body, as well as the strength of the material to fulfill the anchor function. A material that provides the bioresorbability that is desired in the anchor may not provide the initial strength that is required in the anchor. Alternately, a material that may provide the strength that is required in the anchor may not provide the rate of resorbtion that is desired. Further, greater control over the resorbtion rate may be desired, as the wound or incision heals. Accordingly, there is a need for improving the anchor, to provide the desired initial strength and resorbability rate.